[Info-vax] VMS Cobol - GnuCOBOL
David Wade
g4ugm at dave.invalid
Tue Feb 28 06:39:55 EST 2023
On 27/02/2023 23:35, Arne Vajhøj wrote:
> On 2/27/2023 5:42 PM, David Wade wrote:
>> On 27/02/2023 20:58, Arne Vajhøj wrote:
>>> On 2/27/2023 11:49 AM, ultr... at gmail.com wrote:
>>>> On Thursday, February 23, 2023 at 5:05:50 PM UTC-5, Paul Gavin wrote:
>>>>> What, DEC C cannot be debugged?
>>>>> Working on some enhancements in a C based app on Alphas running 8.4.
>>>>> Can get to debugger just fine, step through code, look at data, set
>>>>> break points, etc., even from within ACMS.
>>>>
>>>> never debugged dec c but if the compiler debugger is anything like C
>>>> it is difficult ...
>>>
>>> The VMS C compiler behaves pretty much like other VMS compilers.
>>>
>>> The same VMS debugger is used for C as for any other
>>> (DEC/CPQ/HPE/VSI) language.
>>
>> I feel the issue with debugging "C" is that in order to effectively
>> use the debugger you tend to need to turn down optimisation, but
>> turning down optimization tends to make the code work as you expect.
>> When you turn it up again, undefined behaviour tends to re-emerge.
>
> /DEB/NOOP is not required but tend to make it easier to
> debug because there is a closer correlation between the
> instruction stream and the lines of source code.
>
> And as you point out then that can in fact by itself
> remove symptoms of a bug.
>
> But isn't that the case for all VMS compilers? I know
> I use /DEB/NOOP for both Fortran, Pascal and C when I want
> to debug.
Of course, BUT I feel other languages have fewer places where undefined
behaviour can occur, and so the problem is not so severe.
>
> Arne
>
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